Organic Evaporation
Organic material deposition requires uniform and precise heating with excellent temperature and deposition rate control. This is commonly achieved using a source similar to an effusion furnace (also known as a knudsen cell or k-cell). In this type of source, evaporation of the target material occurs via electrical (Joule) heating of a refractory metal filament coiled around a metal, ceramic, or quartz crucible. The crucible is heated above the melting or sublimation point of the source material to create adequate vapor pressure for deposition.
Source Type
This style of source is very well suited for depositing organic materials, although the right choice of crucibles allows metal deposition as well. Effusion sources have an integrated thermocouple for temperature feedback.
Temperature
The temperature control allows for process flexibility and enables the heating of organic materials to their ideal sweet spot: the temperature just above what is required to create adequate vapor pressure but below its decomposition temperature.
Temperature PID Control
Using the temperature PID control, the sources can be heated to just above the boiling temperature of water to remove moisture from the organic materials which can be one of the major sources of organic film degradation.
We are exceptionally pleased with the two systems we bought from Angstrom and, based on our experience and what I hear from the community, we have made precisely the best decision.
Dr. Luke Brzozowski
University of Toronto